Maneuvering and Simulation of a Ship Entering Into the Vancouver Harbor With an Escort Tug

Abstract

Ship maneuverability and its prediction in the early design stage become possible and important during last 40 years as a result of some marine accidents involving large ships. Maneuverability standards were developed and proposed by International Maritime Organization (IMO) which provides the performance criteria. Ship simulation technology in particular simulation of ship maneuvering advanced well in recent years. With the availability of numerical or experimental hydrodynamics coefficients, maneuverability of different ships can now be simulated with the help of computer programs. Relatively good agreement was reported by various researchers between simulated results and those obtained from real ship trials. It seems that simulation can now identify acceptable ship maneuvering performance in calm seas. However the effects of the wind and the currents are not that well studied and reported while they are always important factors for ship maneuvering especially in restricted waters. In this study “good” ships are identified by a numerical simulation and then their course keeping in restricted area is studied in calm seas and under wind and current conditions. The simulation work is on ESSO OSAKA 278,000DWT tanker, a well tested ship for regular maneuvering test and for entrance in the Vancouver Harbor under wind and current conditions. The effect of escort tugs on such an operation is also quantified. The range of current and wind speeds for “successful” operation is then established. The detailed analysis and comparison with available experimental results are provided.